JP5927308B2 - Lithium-containing glass having high iron oxide content and method for producing the same - Google Patents

Description

  The present application is filed on February 24, 2012, in the United States, entitled “Lithium Contained Glass with High Iron Oxide Content and Method for Making the Same”. Claims the benefit of provisional patent application 61 / 602,909. Application 61 / 602,909 is hereby incorporated by reference in its entirety.

  The present invention relates to glasses having a high iron oxide content and methods for making such glasses, and more particularly from campaigns for making high infrared absorbing glasses, ie glasses having a high reduced iron content. The present invention relates to a method for changing to a campaign for producing glass, i.e. glass having a low reduced iron content, and to the glass produced thereby. In the present specification, a method of changing from a campaign for producing a low infrared absorbing glass, ie a glass having a low reduced iron content, to a campaign for producing a high infrared absorbing glass, ie a glass having a high reduced iron content, and thereby produced Also disclosed is a glass. As used herein, the term “campaign” refers to the use of a predetermined amount of glass batch material or ingredients, for example, but not limited to optical and coloring properties, but having a range of properties, for example, sheet glass. Although it is not limited to a ribbon, it means producing a predetermined amount of glass.

  Of particular interest in the following discussion is the production of lithium-containing glasses. As will be appreciated by those skilled in the art, lithium-containing glasses are typically used as substrates for making ion exchange tempered glasses. One type of lithium-containing glass is disclosed in US Pat. No. 4,156,755 (hereinafter also referred to as “USPN '755”), which is incorporated herein by reference.

In general, iron is not a necessary component for making lithium-containing glasses for ion exchange processes, but small amounts of iron are usually present in lithium-containing glasses as impurities in glass batch components, It is added to the glass batch material so that a lithium-containing glass having the desired properties, not limited to optical and / or coloring properties, is obtained. Total iron oxide content of the Fe ₂ O ₃ commercial glass depends on the product requirements, with respect to what is considered to be transparent glass composition, generally, oxides basis of the weight of the total iron 50 to 1200 one million The range is a fraction (hereinafter also referred to as “PPM”) or 0.005 to 0.12% (hereinafter referred to as “weight percent” or “weight%”). More specifically, the addition of iron can be performed as ferrous iron (FeO) or as ferric iron (Fe ₂ O ₃ ). During melting of glass batch materials, the ferric form of iron ^{(Fe +++)} and ferrous forms of iron ^{(Fe ++)} and reaches equilibrium, the iron ferrous form ^{(Fe ++)} is about 25 to 30 weight The ferric iron form (Fe ⁺⁺⁺⁺ ) is 70 to 75% by weight. Ferric oxide Fe ₂ O ₃ is a strong ultraviolet absorber and acts as a yellow colorant for glass, and ferrous oxide FeO is a strong infrared absorber and acts as a blue colorant for glass. Of particular interest in this discussion is ferrous oxide, FeO.

  If a glass plate, such as, but not limited to, the lithium-containing glass plate (hereinafter also referred to as a “lithium glass plate”) is heated before bending and forming, for example, but not limited to, The composition of the lithium glass plate usually contains ferrous oxide (FeO) in the range of 0.02 to 0.04 wt%, the lithium glass plate has a redox ratio of 0.2 to 0.4 (details below) ). Lithium-containing glass (hereinafter also referred to as “lithium glass”) is a viewing window for infrared equipment, such as but not limited to infrared night vision goggles, or as a component of transparent armor or aerospace windows, When used in the practice of the present invention, ferrous oxide is preferably in the range of 0.001 to 0.010% by weight and lithium glass is in the preferred redox range of 0.005 to 0.10. Have a ratio. The weight percent of ferrous oxide is higher in the heated lithium glass plate in order to increase the absorption of infrared wavelengths and shorten the heating time for the lithium glass plate to reach the bending temperature. The weight percent of ferrous oxide is low in the case of lithium glass used in the viewing window of infrared equipment, in accordance with the teachings of the present invention to increase the percent transmission of infrared energy through the viewing window.

  The campaign for producing high infrared absorption (hereinafter also referred to as “HIRA”) lithium glass moves from the campaign for producing low infrared absorption (hereinafter also referred to as “LIRA”) lithium glass of the present invention, and / or the LIRA of the present invention. One of the drawbacks of moving from a campaign to make lithium glass to a campaign to make HIRA lithium glass is that at the end of one campaign, for example, the end of the campaign to make HIRA lithium glass, The amount of glass that meets the specifications for LIRA lithium glass or HIRA lithium glass produced during the period that ends at the beginning of the campaign to make LIRA lithium glass. Glass that is out of specification for use as LIRA lithium glass and HIRA lithium glass is usually discarded or used as cullet. Those skilled in the art are now aware that the disposal of glass made while changing from one campaign to another is now due to the relatively high batch cost of lithium glass and making unusable or poor quality glass. It can be understood that the time wasted due to the cost.

  Therefore, the disadvantages associated with the change from the campaign of making usable HIRA lithium glass or usable LIRA lithium glass to the campaign of making usable LIRA lithium glass or usable HIRA lithium glass, respectively, are minimized. It would be advantageous to provide a method for reducing or eliminating the above.

One non-limiting embodiment of the invention includes, among other things,

And an oxidizing agent selected from the group of cerium oxide in the range of greater than 0 to 0.50% by weight, manganese oxide in the range of greater than 0 to 0.75% by weight, and mixtures thereof, the redox ratio Relates to a glass composition in the range of 0.005 to 0.15.

Another non-limiting embodiment of the present invention relates to a device for viewing emitted infrared energy, the device including a housing having at least one passage that includes a first open end and a second open end. A lens system for viewing the emitted infrared energy is installed in this passage, and improvements include:
A chemically toughened bulletproof glass lens is mounted adjacent to one end of the passage, the bulletproof glass lens comprising a first surface, an opposing second surface, and the first surface of the bulletproof glass lens. And a glass segment between the second side, the glass segment comprising, among other things,

And an oxidizing agent selected from the group of cerium oxide in the range of greater than 0 to 0.50% by weight, manganese oxide in the range of greater than 0 to 0.75% by weight, and mixtures thereof, the redox ratio Is in the range of 0.005 to 0.15.

Furthermore, another non-limiting embodiment of the present invention provides molten glass in the furnace having FeO in the range of 0.02 to 0.04 wt% and a redox ratio of 0.2 to 0.4. From the molten high-infrared absorbing lithium glass composition in the range, it has FeO in the range of 0.0005 to 0.015 wt%, the redox ratio is in the range of 0.005 to 0.15, and oxidizes FeO With respect to a method of converting to a molten low infrared absorbing lithium glass composition having a predetermined amount of a first oxidant, the method includes, among others:
A molten low infrared radiation having FeO in the range of 0.0005 to 0.015 wt%, having a redox ratio in the range of 0.005 to 0.15, and having a predetermined amount of a first oxidant that oxidizes FeO Providing a glass batch material having components that provide an absorbent lithium glass composition;
Adding a second oxidant to the glass batch material in an amount equal to 1 or 2 times the amount of the first oxidant over a period of time to oxidize FeO in the molten glass in a furnace;
And a step of stopping execution of the above steps after a predetermined period.

Still further, a non-limiting embodiment of the present invention is a laminated transparency comprising a plurality of glass plates, for example windshields for aircraft and land vehicles, wherein at least one of the glass plates is chemically strengthened. And optionally a plastic plate, which are laminated together by a plastic intermediate layer, at least one of the glass plates, inter alia:

And an oxidizing agent selected from the group of cerium oxide in the range of greater than 0 to 0.50% by weight, manganese oxide in the range of greater than 0 to 0.75% by weight, and mixtures thereof, the redox ratio Relates to the above laminated transparency having a glass composition in the range of 0.005 to 0.15.

  The present invention further provides a glass batch material comprising, inter alia, a component that provides a molten high infrared absorbing lithium glass composition and a predetermined amount of a first reducing agent to increase FeO; Adding a second reducing agent to the material in an amount equal to one or twice the amount of the first reducing agent over a period of time to increase FeO in the molten glass in the furnace; after the period of time; The step of discontinuing the implementation of the foregoing steps, wherein the molten glass in the furnace has FeO in the range of 0.0005 to 0.015 wt% and the redox ratio is in the range of 0.005 to 0.10. High infrared absorption lithium having a FeO in the range of 0.02 to 0.04 wt% and a redox ratio in the range of 0.2 to 0.4 from the molten low infrared absorption lithium glass composition To a method of changing the Mugarasu composition.

1 is a plan view of a cross section of a glass melting furnace connected to a glass forming chamber of the type used to make a float glass ribbon according to the present invention. 1 is a plan view of a cross section of a glass melting furnace connected to a glass forming chamber of the type used to make a float glass ribbon according to the present invention.

FIG. 1B is an elevation cross-sectional side view of the glass melting chamber shown in FIG. 1A.

FIG. 3 is a graph showing redox values and approximate ferrous (FeO) content as a result of oxidation of FeO with various amounts of CeO ₂ and MnO ₂ .

₂ is a graph showing oxidation of ferrous iron (FeO) with various amounts of CeO ₂ and MnO ₂ .

1 is a cross-sectional side view of a dark field scope of the present invention having a protective lens made according to the present invention. FIG.

1 is a side view of a laminated ballistic lens or window incorporating features of the present invention. FIG.

  As used herein, space or direction terms such as “inside”, “outside”, “left”, “right”, “up”, “down”, “horizontal”, and “vertical” The present invention relates to what is depicted above. However, it should be understood that the present invention can assume various alternative orientations, and thus such terms are not to be considered limiting. Further, it is to be understood that all numerical values such as dimensions and physical properties used in the specification and claims are modified in all cases by the term “about”. Thus, unless indicated to the contrary, the numerical values set forth in the following specification and claims may vary depending on the properties desired and / or desired by the present invention. At a minimum, rather than trying to limit the application of the equivalent doctrine of the claims, each numerical parameter applies to the reported significant figures and applies the usual rounding technique. Should at least be interpreted. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a range described as “1 to 10” should be considered to include a minimum value of 1 and a maximum value of 10 and any and all subranges between them; Includes all sub-ranges starting from above and ending with a maximum value of 10 or less, for example 1 to 6.7, or 3.2 to 8.1, or 5.5 to 10. Also, as used herein, the term “mounted on” means mounted on but not necessarily in surface contact. For example, an article or component of an article is “mounted on” another article or article component means that there is material between these articles or between the components of these articles, respectively. It does not exclude that.

  Before discussing some non-limiting embodiments of the present invention, the invention is capable of other embodiments, and the invention is not limited to the specific non-limiting examples shown and discussed herein. It is understood that the details are not limited to the specific embodiments. Furthermore, the terminology used herein to discuss the present invention is for purposes of explanation and is not intended to be limiting. Still further, unless otherwise indicated, like numbers refer to like elements in the following discussion.

  Non-limiting embodiments of the present invention are disclosed using the lithium glass composition disclosed in USPN '755, but the present invention is not so limited, and the present invention has a high iron oxide content, For example, but not limited to, producing soda-lime silicate glass having ferrous oxide in the range of 0.02 to 0.04% by weight and redox ratio in the range of 0.2 to 0.4. From one campaign, it has a low iron oxide content, such as, but not limited to, ferrous oxide in the range of 0.001 to 0.010 wt% and a redox ratio in the range of 0.005 to 0.15. It can be implemented to change to another campaign to make one soda lime silicate glass.

As now understood, Fe ₂ O ₃ and / or FeO can be added as a colorant or modifier. Although the total amount of iron present in the lithium glass disclosed herein is expressed in terms of Fe ₂ O ₃ according to standard analytical practice, all iron actually takes the form of Fe ₂ O _3. Does not suggest that. Similarly, the amount of ferrous iron is reported as FeO even though it may not actually be present in the glass as FeO. To reflect the relative amounts of ferrous and ferric iron in the glass compositions disclosed herein, the term “redox ratio” refers to the amount of ferrous iron expressed as FeO. , And the value divided by the amount of total iron expressed as Fe ₂ O ₃ . Further, unless otherwise indicated, the term “total iron” herein shall mean total iron expressed with respect to Fe ₂ O ₃ , and the term “FeO” shall be the first expressed with respect to FeO. It shall mean iron in the iron state.

The range of materials or components of the lithium-containing glass disclosed in USPN '755 is listed in Table 1 below.

  The weight percent of all oxides in the glass, excluding lithium, is measured using X-ray fluorescence microscopy (also known as “XRFS”). The weight percent of lithium oxide in the glass is measured by atomic absorption.

Small amounts (up to a total of about 5% by weight) of other glass forming materials and glass modifiers or colorants such as MgO, MnO, TiO ₂ , Sb ₂ O ₃ , As ₂ O ₃ , K ₂ O, PbO, ZnO , And CaO and mixtures thereof. As will be appreciated by those skilled in the art, Sb ₂ O ₃ and As ₂ O ₃ are oxidizing agents for the glass sheet drawing process, but depending on the reduction state of the float glass chamber, Sb ₂ O ₃ and As ₂ O ₃ are And is reduced to arsenic metal, which is incompatible with use in the float glass process.

  In one non-limiting embodiment of the present invention, if a lithium glass plate having the composition of Table 1 is heated prior to bending and / or shaping of the plate, for example, but not limited to this consideration, lithium The glass composition contains, in addition to the components in Table 1, ferrous oxide in the range of 0.02 to 0.05% by weight, preferably in the range of 0.03 to 0.038% by weight, and the redox ratio. Is in the range of 0.2 to 0.4, preferably in the range of 0.2 to 0.35 (hereinafter, the aforementioned glass is also referred to as “high infrared absorbing lithium glass” or “HIRA lithium glass”). During the campaign to make HIRA lithium glass, sulfate (sulfate) and carbon are added to the glass batch components. Sulfate and carbon additions are made to increase the ferrous oxide content so that the molten glass is maintained within the desired redox ratio range.

In another non-limiting embodiment of the present invention, a lithium-containing glass having the composition of Table 1 is used as a viewing window for infrared equipment, such as, but not limited to, infrared night vision goggles, scopes, such as rifle scopes. If so, the lithium glass composition contains the components in Table 1. As shown, iron oxides are not listed as ingredients, but as will be appreciated by those skilled in the art, iron, eg ferrous oxide, is a contaminant found in batch materials, eg glass cullet. Is expected to be present in the glass. As long as ferrous iron can be present, the present invention provides the glass of the present invention in the range of 0.0005 to 0.015% by weight, preferably in the range of 0.001 to 0.010% by weight in addition to the composition of Table 1. It is intended to contain ferrous oxide and have a redox ratio in the range of 0.005 to 0.15, preferably in the range of 0.005 to 0.10 (hereinafter said glass is referred to as “low infrared absorption” Also referred to as “lithium-containing glass” or “LIRA lithium glass”). Total iron (Fe ₂ O ₃ ) is expected to be in the range of 50 to 200 ppm Fe ₂ O ₃ . During the campaign to make LIRA Lithium Glass, add oxidizer additions to the glass that are compatible with the selected glass making process, eg cerium oxide, manganese oxide, antimony oxide, arsenic oxide, and combinations thereof into glass batch components Add so that the molten glass is maintained within the redox ratio range of the LIRA lithium glass.

  As discussed above, the weight percent of ferrous oxide increases the absorption of infrared wavelengths to reduce the heating time for the glass to reach the bending temperature or provide some level of solar thermal control. Higher in glass, the ferrous weight percent enhances the field of view of infrared emitting objects by reducing the absorption of infrared energy in the infrared viewing range and increasing the percent transmission of infrared energy in the infrared viewing range. To be lower with LIRA lithium glass. For clarity purposes, the ultraviolet wavelength range in the electromagnetic spectrum is 300 to 380 nanometers (hereinafter also referred to as “nm”); the visible wavelength range is 380 to 780 nm; the near infrared wavelength range is 800 to 2100 nm. It is. The infrared viewing wavelength range is device dependent. In one non-limiting embodiment of the invention, the infrared viewing wavelength range is 400 to 920 nm of the electromagnetic spectrum. In the practice of the present invention, the LIRA lithium glass preferably has a visible light transmission of 88% or more, more preferably a visible light transmission of more than 89%, most preferably a visible light transmission of more than 90%; Infrared transmittance, more preferably more than 85% infrared transmission, most preferably more than 90% infrared transmission; more than 80% infrared viewing transmittance, more preferably more than 85% infrared viewing transmittance, most Preferably, it has an infrared field transmittance of more than 90%.

  Further, in the practice of the present invention, the HIRA lithium glass has a visible light transmission of less than 88%; an infrared transmission of less than 75%; and an infrared field transmission of less than 80%.

  The spectral characteristics of the LIRA lithium glass obtained above are reported at a thickness of 0.223 inches (5.7 millimeters). Visible light transmission is determined using CIE standard light source A with a 2 ° observer in the wavelength range of 380 to 780 nanometers. Infrared transmission is determined using Parry Moon air mass 2.0 direct solar irradiation data in the wavelength range of 800 to 2100 nm. The field transmittance is determined using the relative spectral illumination of the CIE standard light source A and the field device response function in the wavelength range 400 to 930 nm.

  The LIRA and HIRA lithium glasses of the present invention use conventional non-vacuum refined float glass systems, such as, but not limited to, the types shown in FIGS. 1 and 2, or vacuum refined float glass systems, such as However, it can be made using the types disclosed in US Pat. Nos. 4,792,536 and 5,030,594, which are incorporated herein by reference.

  Referring to FIGS. 1A, 1B, and 2, a conventional non-vacuum refining furnace 20 that continuously feeds, cross-tanks, and melts glass is made by a bottom 22, roof 24, and sidewalls 26 made of a refractory material. Includes a formed housing. The HIRA or LIRA lithium glass batch material 28 is introduced via an inlet opening 30 (see FIG. 2) into an extension 32 of the furnace 20 known as a fill dog house in any convenient or conventional manner to provide molten glass. A blanket 34 floats on the surface 36 of 38 (see FIG. 2). The overall progression of the glass shown in FIGS. 1A and 1B is from left to right in the figures, and is the inlet end 39 (of a glass forming chamber 40 of the type used in the art for making float glazing. (See FIG. 1B).

  A flame (not shown) for melting the batch material 28 and heating the molten glass 38 arises from burner ports 42 spaced along the side wall 26 (see FIG. 2), Directed over and over the surface 36. As is known to those skilled in the art, during the first half of the heating cycle, flames are emitted from nozzles 43 (see FIG. 2) at each of the ports on one side of tank 20, at which time the furnace exhaust gas is Move in the port on the other side of the furnace. During the second half of the heating cycle, the port functions are reversed, the exhaust gas port being the combustion port, and the combustion port being the exhaust gas port. The combustion cycle for a furnace of the type shown in FIGS. 1A, 1B, and 2 is well known in the art and will not require further consideration.

  As will be appreciated by those skilled in the art, the present invention employs a mixture of air and fuel gas or a mixture of oxygen and fuel gas to generate a flame so that the batch material and molten glass are heated. Contemplate. For a discussion of the use of oxygen and fuel gas in a glass melting furnace, the name “Use of Photovoltaic for Waste Heat Recovery”, which is incorporated herein by reference. U.S. Patent Application Publication No. 2009-0205711 (A1).

  The glass batch material 28 moving downstream from the batch feed end or doghouse end wall 46 melts in the melting section 48 of the furnace 20, and the molten glass 38 passes through the waist 54 (see FIG. 1B) in the refining section of the furnace 20. Move to 56. In the refining section 56, bubbles in the molten glass 38 are removed, and the molten glass 38 is mixed or homogenized as it passes through the refining section 56. Molten glass 38 is delivered from refining section 56 onto a pool of molten metal (not shown) entering glass forming chamber 40 in any convenient or conventional manner. As the delivered molten glass 38 moves through the glass forming chamber 40 and onto a pool of molten metal (not shown), the molten glass is sized and cooled. A glass ribbon (not shown) sized stably in dimension leaves the glass forming chamber 40 and moves into an annealing slow-down kiln (not shown). Glass making devices of the type shown in FIGS. 1A, 1B and 2 and the types discussed above are well known in the art and will not require further consideration.

  Next, as will be appreciated by those skilled in the art, when changing from a campaign to make HIRA lithium glass to a campaign to make LIRA lithium glass, furnace 20 (FIGS. 1A, 1B) at the end of the campaign to make HIRA lithium glass. , And 2), the ferrous iron in the molten HIRA lithium glass is preferably in the range of 0.0005 to 0.015% by weight, more preferably in the range of 0.001 to 0.010% by weight. The redox ratio is preferably in the range of 0.005 to 0.15, more preferably in the range of 0.005 to 0.10. In the practice of the present invention, for example, the conversion from molten HIRA lithium glass in a 1850 ton furnace to molten LIRA lithium glass takes place in 3 to 4 days, whereas only LIRA lithium glass batch components without oxidant It takes about 2 weeks to convert by adding.

In the practice of the present invention, the change from molten HIRA lithium glass to molten LIRA lithium glass can be done in 3 to 4 days using an oxidant. In one non-limiting embodiment of the invention, cerium oxide (CeO ₂ ) and / or manganese oxide (MnO ₂ ) is used to oxidize ferrous iron to ferric iron, as discussed above. As such, it is compatible with the glass making process shown in FIGS. 1A, 1B, and 2. In the preferred practice of the present invention, cerium oxide (CeO ₂ ) is used to oxidize ferrous iron to ferric iron, which, as demonstrated by the experiments performed, oxidizes cerium oxide (CeO ₂ ). This is because the oxidizing agent is more effective than manganese (MnO ₂ ).

More specifically, a glass sample shown in Table 2 (also referred to as “control sample”); a glass sample shown in Table 1 with CeO ₂ added (also referred to as “cerium sample”), and MnO ₂ added. The glass samples shown in Table 1 (also referred to as “manganese samples”) were produced. Samples 1-5 are cerium samples with varying amounts of cerium oxide, and samples 6 and 7 are manganese samples with varying amounts of manganese oxide.

FIG. 3 is a plot showing the redox ratio and approximate FeO content, and FIG. 4 shows the ferrous oxide content of the control sample and samples 1-7 on the ordinate (y-axis) and the weight of cerium oxide and manganese oxide. It is a plot which shows% on an abscissa (x-axis). Control sample data points are on the y-axis. In the preferred practice of the invention, cerium oxide is used to oxidize ferrous iron to ferric iron, which is an oxidant that is more effective than manganese oxide, as shown in FIGS. Yes, because cerium oxide "decolorizes" the glass. More specifically, cerium oxide is not a glass colorant, cerium oxide is a strong oxidant in glass, and its function in decolorized glass is to convert iron in the ferrous state (Fe ⁺⁺ ). It is to oxidize to iron in the ferric (Fe ⁺⁺ ) state. Cerium oxide is useful for decolorizing the remaining traces of ferrous iron, but the use of cerium oxide is limited, for example, but not limited to this discussion, exposing LIRA lithium glass to sunlight. Exerts a solarization effect on the glass resulting from photo-oxidation from Ce ⁺⁺⁺⁺ to Ce ⁺⁺⁺ and ^{photoreduction} from Fe ⁺⁺ to Fe ⁺⁺ . As will be appreciated by those skilled in the art, the light reduction to Fe ⁺⁺ from solarization effects and Fe ⁺⁺⁺ of cerium, and increases the absorption of the glass to reduce the transmittance in the visible and IR range of the electromagnetic spectrum. Since the reduction in visible and infrared transmission is less than 1%, cerium oxide is preferred for oxidizing ferrous iron. Nevertheless, the present invention contemplates adding manganese oxide in place of cerium oxide and adding a mixture of manganese oxide and cerium oxide.

In the practice of the present invention, cerium oxide in the range of greater than 0 to 0.50% by weight can be used; a range of 0.02 to 0.45% by weight is preferred, 0.04 to 0.40% by weight The range of is more preferable. Other ranges for cerium oxide include, but are not limited to, 0.01 to 0.15 wt%; 0.02 to 0.10 wt%, and 0.03 to 0.07 wt%. Absent. Manganese oxides in the range of greater than 0 to 0.75% by weight can be used, with a range of 0.02 to 0.50% by weight being preferred, and an amount of 0.04 to 0.45% by weight being more preferred. As now understood, a mixture of CeO ₂ and MnO ₂ can be used in the practice of the present invention to oxidize ferrous iron. In general, for a given range of MnO ₂ , 1 part of CeO ₂ replaces 1.10 to 1.50 parts of MnO ₂ , and for a given range of CeO ₂ , MnO ₂ 1.10 to 1. 5 parts replace 1 part of CeO ₂ . Glasses with lower total iron content can use lower amounts of cerium oxide or manganese oxide. The amount of cerium oxide or manganese oxide in the present specification, even these components can not actually present in the glass as CeO ₂ or MnO _2, shall mean the total cerium or manganese, respectively, CeO ₂ or MnO ₂ Represented as:

In the following non-limiting embodiment of the present invention, Campaign A is active to make HIRA lithium glass. Campaign A is designated to end and Campaign B begins to produce LIRA lithium glass. Table 3 shows the composition of the HIRA lithium glass being produced and the composition of the LIRA lithium glass to be produced.

  During the execution of Campaign A, the HIRA lithium glass batch material is fed into furnace 20 (see FIGS. 1A, 1B, and 2), melted, refined, and the refined glass is in a glass forming chamber as discussed above. Moving into 40, HIRA lithium glass having the composition shown in Table 3 is made. At the designated time when Campaign A ends, the glass batch material for the LIRA Lithium Glass moves into the melting section 48 of the furnace 20 and begins Campaign B as discussed above. During the first 36 hours of Campaign B, the batch material for LIRA lithium glass was formulated and cerium oxide was specified in the range of 0.04-0.90 wt%, ie for lithium glass in Table 3. Lithium glass having twice that of cerium oxide is obtained. After 36 hours, a batch material for LIRA lithium glass is blended to obtain lithium glass having cerium oxide in the range of 0.02 to 0.45% by weight (see Table 3).

  In one embodiment of the invention, cerium oxide is obtained in the glass by adding cerium carbonate to the batch material. To make the LIRA lithium glass of Table 3, cerium carbonate in the range of 0.033 to 0.75 wt% is added to the batch material. For the original LIRA lithium glass batch material (first 36 hours of Campaign B), cerium carbonate in the range of 0.066 to 1.50 wt% is added to the batch material. The LIRA lithium glass of Table 3 is made by running Campaign B with cerium carbonate reduced to 0.033-0.75 wt% at the end of the first 36 hours of Campaign B. Additional cerium carbonate during the first 36 hours of Campaign B is performed to oxidize ferrous iron in the melting section 26 and the purification section 56 of the furnace 20. At the end of the first 36 hours, the glass batch material for the LIRA lithium glass moves into the melting section 46 of the furnace 20 as discussed above.

  In another non-limiting embodiment of the present invention, if the glass produced has sufficient UV absorber, such as cerium oxide, after a 36 hour pulse, a sufficiently small batch of iron, such as that limited to the present invention. If, however, a batch having less than 0.0005% by weight is used to make a glass that does not contain a UV absorber, no further addition of cerium carbonate is necessary.

The present invention is not limited to the number or length of pulses or the weight percent of cerium oxide in the pulses. In the practice of the present invention, the weight percent of cerium oxide in the pulse is typically 2 to 3 times the weight percent of cerium oxide in the LIRA lithium glass batch, and the number of pulses is typically 1 or 2. The duration of each pulse can be varied as required. The above procedure for the use of CeO ₂ to oxidize ferrous iron when changing from Campaign A to Campaign B changes from Campaign A to make LIRA lithium glass to Campaign B to make LIRA lithium glass. Therefore, it is applicable to the practice of the present invention using MnO ₂ or a mixture of CeO ₂ and MnO ₂ . The procedure is the same, since the cerium oxide is an effective oxidizing agent than manganese oxide, and MnO _2, increasing the weight percent of the mixture of CeO ₂ and MnO _2.

The present invention is not limited to the addition of an oxidant, such as, but not limited to, CeO ₂ , a mixture of MnO ₂ and CeO ₂ and MnO ₂ to the batch material. The addition of additional oxidant to the molten glass of the refiner 56 in position or to the molten glass of the melter 36 is contemplated.

In another non-limiting embodiment of the present invention, a campaign for making LIRA lithium glass by adding a reducing agent to reduce ferric iron to ferrous is a campaign for making HIRA lithium glass. Be changed. The reducing agent can be used in the practice of the present invention, carbon, carbon-containing material, such as, but not limited to graphite, sucrose _{(C 12 H 22 O 11)} , coal, silicon metal, and tin oxide (SnO ₂ ), but is not limited thereto. Additional non-limiting embodiments of the present invention include campaign modifications to make different types of soda lime silicate glass or any other type of glass, such as soda lime silica from HIRA or LIRA lithium glass. Modifications to the salt glass or vice versa are included, but are not limited to these.

  The use of the HIRA and LIRA lithium glasses of the present invention produced during campaigns A and B is not limited to the present invention, but includes ground, air, outer space, water and underwater, vehicle windows; commercial and residential Can be engineered for use in window transparency, solar collector covers, and bulletproof viewing windows. HIRA lithium glass is commonly used for viewing windows using a source that provides visible light and is generally not recommended for viewing infrared energy from objects, for example, the use of HIRA lithium glass is a night vision goggle. Not recommended for. For dark field equipment, LIRA lithium glass is recommended to protect the lens system of this dark field equipment, such as, but not limited to, the dark field goggles and the dark field scope lens system. More specifically, referring to FIG. 5, a dark field rifle scope 70 is shown having a tube 72 and a dark field magnification lens system 74 mounted in a passage 76 of the tube 72. A ballistic lens 78 made of chemically strengthened LIRA lithium glass is attached to the end of the tube at a distance from the lens system 74. In this arrangement, the lens system 74 is protected from breakage by the chemically strengthened LIRA lithium glass lens of the present invention. LIRA lithium glass can also be used for special applications including but not limited to the present invention, including furniture, appliances, and use in shower doors.

  Referring to FIG. 6, a non-limiting embodiment of a bulletproof lens or window 84 is shown. The window 84 includes a plurality of LIRA lithium chemically strengthened glass plates 86 and a plastic plate 88 laminated together by a plastic interlayer material 90 of the type used in the lamination art.

  In the practice of the non-limiting embodiments of the present invention, the LIRA and HIRA lithium glasses can be any type of coating, such as, but not limited to, an environmental coating, photocatalyst that selectively passes light and energy in a range of wavelengths. A film, or a water-reducing film, or a transparent conductive oxide of the type disclosed in US Pat. Nos. 5,873,203 and 5,469,657, incorporated herein by reference, for example, Or may be coated.

  The present invention is not intended to be limited to the embodiments of the invention presented and discussed above, which are presented for illustrative purposes only, and the scope of the invention is from the following claims and from this application. Limited by any additional claims appended to an application having a direct or indirect derivation thereof.

Claims (22)

A redox ratio comprising : cerium oxide in the range of greater than 0 to 0.50 wt%, manganese oxide in the range of greater than 0 to 0.75 wt%, and mixtures thereof Is in the range of 0.005 to 0.15.   The glass composition of claim 1 wherein the cerium oxide is in the range of 0.01 to 0.15 wt%.   The glass composition according to claim 1, wherein FeO is in the range of 0.001 to 0.010 wt%. The glass composition of claim 1, wherein Fe ₂ O ₃ (total iron) is in the range of 50 to 200 ppm.   The glass composition of claim 1, wherein the redox ratio is in the range of 0.005 to 0.10.   The oxidant is selected from the group of cerium oxide in the range of 0.02 to 0.45 wt%, manganese oxide in the range of 0.02 to 0.50 wt%, and mixtures thereof. Glass composition.   FeO is in the range of 0.001 to 0.010% by weight, total iron is in the range of 50 to 200 ppm, redox ratio is in the range of 0.005 to 0.10, and the oxidizing agent is from 0.02. The glass composition of claim 1 selected from the group of cerium oxide in the range of 0.45 wt%, manganese oxide in the range of 0.02 to 0.50 wt%, and mixtures thereof. A device for viewing emitted infrared energy, the device including a housing having at least one passageway, the passageway having a first open end and a second open end, for viewing the emitted infrared energy. has a lens system, improvements, mounted adjacent one end of the passageway, consist of chemically toughening bulletproof glass lens, the bulletproof glass lens has a first surface, a second surface opposite When, and a glass segment between the first surface and the second surface of the bulletproof glass lenses, glass segments,

And an oxidizing agent selected from the group of cerium oxide in the range of greater than 0 to 0.50% by weight, manganese oxide in the range of greater than 0 to 0.75% by weight, and mixtures thereof, the redox ratio Wherein said device is in the range of 0.005 to 0.15.   The lens has a visible light transmission greater than 88%, an infrared transmission greater than 80%, and an infrared field transmission greater than 80%, the transmission being 0.223 inches (5.7 millimeters) thick. The device according to claim 8, which relates to a glass lens.   The device of claim 8, wherein the glass segment has a FeO in the range of 0.001 to 0.010 wt%.   The device of claim 10, wherein the redox ratio of the glass segment is in the range of 0.005 to 0.10.   9. The oxidant is selected from the group of cerium oxide in the range of 0.02 to 0.45 wt%, manganese oxide in the range of 0.02 to 0.50 wt%, and mixtures thereof. Devices. The molten glass in the furnace is composed of 59 to 63% by weight SiO ₂ , 10 to 13% by weight Na ₂ O, 4 to 5.5% by weight LiO ₂ , 15 to 23% by weight. Al ₂ O ₃ , ZrO ₂ in the range of 2 to 5% by weight , FeO in the range of 0.02 to 0.04% by weight and a redox ratio in the range of 0.2 to 0.4 the infrared absorbing lithium glass composition has a FeO ranging from 0.0005 to 0.015 wt%, in the range of from redox ratio 0.005 0.10, and a first oxidation Ru is oxidized to FeO A method of changing to a molten low-infrared absorbing lithium glass composition having an agent,
Has a FeO ranging from 0.0005 to 0.015 wt%, in the range of from redox ratio 0.005 0.10, and melting the low infrared-absorbing lithium having a first oxidizing agent to FeO Ru is oxidized Providing a glass batch material having components that provide a glass composition;
The glass batch materials, the first and the second oxidant to added pressure in an amount equal to 1 or 2 times the amount of the oxidizing agent, the step of oxidizing the FeO in the molten glass in a furnace;
Discontinuing the step of supplying the glass batch material and the step of adding the second oxidant to oxidize FeO ;
It said method comprising. First and second oxidizer is selected from the group of CeO ₂ and MnO _2, and mixtures thereof The method of claim 13. The method of claim 14, wherein the first and second oxidants are each CeO ₂ . The method of claim 14, wherein the first and second oxidants are each MnO ₂ . 14. A method of producing glass by the method of claim 13, wherein the molten low infrared absorbing lithium glass composition has FeO in the range of 0.001 to 0.010 wt% and a redox ratio of 0.00. A method in the range of 005 to 0.10 and having a predetermined amount of the first oxidant . A laminated transparency comprising a plurality of chemically strengthened glass plates and optionally a plastic plate laminated together by a plastic interlayer, wherein at least one of said glass plates is

A redox ratio comprising : cerium oxide in the range of greater than 0 to 0.50 wt%, manganese oxide in the range of greater than 0 to 0.75 wt%, and mixtures thereof The laminated transparency having a glass composition wherein is in the range of 0.005 to 0.15.   19. The laminated transparency of claim 18, selected from the group of aircraft windows and ground, air, outer space, water and underwater vehicle windows.   The laminated transparency of claim 18, wherein the window is a windshield. FeO is in the range of 0.001 to 0.010% by weight, total iron is in the range of 50 to 200 ppm, redox ratio is in the range of 0.005 to 0.10, and the oxidizing agent is from 0.02. 19. The laminated transparency of claim 18, selected from the group of cerium oxide in the range of 0.45% by weight, manganese oxide in the range of 0.02 to 0.50% by weight, and mixtures thereof. The glass composition according to claim 1, wherein the oxidizing agent is a mixture of cerium oxide and manganese oxide, and the total concentration of cerium oxide and manganese oxide is in the range of 0.02 to 0.675% .